In the communications industry where it becomes necessary to interconnect seemingly countless numbers of insulated conductors, solderless electrical connectors are used widely. One type of solderless connector generally includes an electrically conductive element, which is commonly referred to as a slotted beam contact element and which comprises a waist portion having a beam extending from opposite sides thereof with each of the beams bifurcated to provide a slot for receiving an insulated conductor. See, for example, U.S. Pat. No. 3,798,587 issued Mar. 19, 1974 to B. C. Ellis, Jr. et al and U.S. Pat. No. 3,858,158 issued Dec. 31, 1974 in the names of R. W. Henn et al. The spacing between the furcations of each beam is such that facing, inner edge surfaces thereof which define the slot penetrate the insulation of an insulated conductor which is moved into the slot to establish electrical engagement between the conductor and the furcations. Because of their resiliency, the bifurcated portions of the beam tend to move toward each other after a conductor has been moved into the slot to clamp the conductor tightly.
In the prior art, slotted beam contact elements have been formed along a metallic strip by the step of punching the strip to form central waist portions having beams extending bilaterally thereof. Each beam may be lanced to bifurcate the beam with opposing lanced surfaces of the furcations defining a conductor-receiving slot. The step of lancing invariably moves one of the furcations out of the plane of the contact element thereby impairing the connection process when a conductor is moved into the slot. Also, the step of lancing makes it difficult to control the shape of the opposing lanced surfaces of the furcations which define the slot, and forms burrs on the lanced surfaces which may deform a condcutor that is moved into the slot. In the alternative, each conductor-receiving slot is formed by punching a narrow slot in a beam; however, difficulties have been encountered in punching narrow width slots through relatively thick strips of metal.
Inasmuch as conductors which are connected with slotted beam contact elements are exposed to a wide range of conditions, the conductors are insulated with different materials. Rather than manufacture different kinds of slotted beam contact elements which are usable with different types of insulation, it is more economical to manufacture a contact element which is capable of tearing, penetrating or slicing through a variety of types of insulation to establish an electrical connection and which is capable of maintaining a tight connection. This is accomplished by shaping the opposing inner edge surfaces of the beam furcations to a predetermined configuration. However, as noted hereinbefore, the satisfactory shaping of these surfaces has not been accomplished when the furcations are formed by the step of lancing or by the punching of a narrow slot in the beam.
Also, it may be important that the inner edge surfaces of the furcations be plated with a corrosion-resistant material such as, for example, gold or solder. This is difficult to do in the conventional process of forming the beams and then lancing them to provide the slots because of the relatively small gap between the furcations.
These problems have been overcome to some extent by the techniques shown in U.S. Pat. No. 4,136,628, which issued on Jan. 30, 1979 in the names of C. McGonigal and J. E. Voytko and which is incorporated by reference hereinto. Contact elements are configured along a strip which is moved through a plurality of work stations of a punch and die apparatus. The forming is accomplished such that the furcations at each end of each beam are spaced apart. This allows the facing furcation edge surfaces at each end to be specially configured after which the furcations are moved toward each other and then pivoted about their free end portions, which are touching, to form a slot having a predetermined configuration.
Although the just-described technique provides contact elements having a desired slot configuration, it is not desirable to have the end portions of the furcations act as pivot points for the closing. This may cause damage to those end portions and result in deformed entrances to the conductor-receiving slots between the furcations. What is needed and what seemingly is not provided by the prior art are methods and apparatus for making contact elements first with the furcations in an open position to allow configuring and then for closing them without damaging them.